Question: $ C = \left[\begin{array}{rrr}0 & 2 & 2 \\ 2 & 0 & 1 \\ 0 & 1 & 2\end{array}\right]$ What is $ C^{-1}$ ?
$ = \left[\begin{array}{rrr}\frac{1}{4} & \frac{1}{2} & -\frac{1}{2} \\ 1 & 0 & -1 \\ -\frac{1}{2} & 0 & 1\end{array}\right]$